The digital PCR revolution
“Like finding a needle in a haystack” is an overused expression, but when it comes to some biological scavenger hunts, it fits. Researchers studying rare variant biomarkers often find themselves on the lookout for faint genetic signals against an overwhelming background, sometimes as little as a single positive in 100,000 negatives or more. Such a situation cries out for polymerase chain reaction (PCR), a technique uniquely capable of capturing the proverbial needle. But standard PCR won’t do—it is a qualitative technique—and neither will quantitative real-time PCR (qPCR), which often lacks the necessary accuracy and sensitivity. These days, there’s a third and increasingly popular option: digital PCR (dPCR). By discretizing those 100,000 molecules in a large number of individual reactions, dPCR makes the rare positive surprisingly easy to find… Read more at sciencemag.org (PDF).
Biotechnically Speaking 